After locking my Fabia and when the immobiliser kicks in, the rear lights and front side lights come on and flicker. 

 

Is this an immobiliser problem?

 

The battery went flat today after a few hours of the lights flickering. 

 

Could it be battery problem, key fob or something else 🤔 

 

 

The battery doesn't sound like it was in very good condition, you should start by fully charging it or fitting a new one.

Okay will do that.

Plugged it into a meter and was reading 12.4v.

However it is the original battery 🔋 so am sure its due to be renewed 

Fabia 1,2 2011 12000 mil, original batteriet fortfarande.